Hello,
It´s a nice workaround that I already though about, but it´s complicated to manage I think. You would have many playlists and many pages if you want to show only the next classes (hiding past ones). The idea to have a single schedule to manage Fraab-like is easier. In the old version of info-beamer where all these plugins didn´t exist I did modify an old example in git to do exactly this.
I think it´s something that could be interesting for many businesses (schools of any type) but in any case, if you have some updated documentations on what is expected when writing a plugin I would be more than glad. I would fork the repo modify it and, if I manage to do something nice, share it with you.
Thanks for your help in any case.